The family Filoviridae, which includes Marburg virus and five species of Ebola virus (EBOV), four of which are Zaire, Sudan, Ivory Coast and Bundibugyo (Towner, J. S., et al., Newly discovered ebola virus associated with hemorrhagic fever outbreak in Uganda. PLoS Pathog, 2008. 4(11): p. e1000212), causes severe hemorrhagic fever in humans, with a lethality of up to 90%. Outbreaks of Ebola (EBOV) and Marburg (MARV) infections occur in Central Africa on a regular basis (Groseth, A., H. Feldmann, and J. E. Strong, The ecology of Ebola virus. Trends Microbiol, 2007. 15(9): p. 408-16). Sequences of EBOV Zaire identified in wild apes during the 2003-2005 outbreaks in Gabon and The Democratic Republic of Congo (DRC) demonstrated circulation of several lineages of the virus and recombination events between the viruses (Wittmann, T. J., et al., Isolates of Zaire ebolavirus from wild apes reveal genetic lineage and recombinants. Proc Natl Acad Sci USA, 2007. 104(43): p. 17123-7). Similarly, sequence analysis of MARV isolated during the 1999 outbreak in the DRC demonstrated the simultaneous circulation of multiple genetic lineages with up to 21% nucleotide divergence (Towner, J. S., et al., Marburgvirus genomics and association with a large hemorrhagic fever outbreak in Angola. J Virol, 2006. 80(13): p. 6497-516; Bausch, D. G., et al., Marburg hemorrhagic fever associated with multiple genetic lineages of virus. N Engl J Med, 2006. 355(9): p. 909-19). Sequence analysis of multiple MARV isolates in bats collected during the 2007 outbreak also demonstrated the simultaneous circulation of multiple diverse lineages of the virus, including those identical or almost identical to human isolates (Towner, J. S., et al., Isolation of genetically diverse Marburg viruses from Egyptian fruit bats. PloS Pathog, 2009. 5(7): p. e1000536). These data suggest a broad distribution and significant diversity of filoviruses. There is an urgent need for development of treatments against filoviruses.